Precisely!

There are a few restaurants we frequent enough that the managers (and some wait-staff when not seated in their section) will stop to welcome us or thank us for our business. Of course, this almost inevitably includes an outreached hand.

We've recently taken to extending our fist in response to offer a "fist bump". Most of them immediately understand and react in kind.

Think about flu season and all those germs that transfer from one's hand, to a waiters hand, to your plate, to your mouth.